Gas-compressing pump



(No Model.) 3 Sheets-Sheet 1.

T. PARNS W ORTH. GAS GOMPRESSING PUMP.

N0. 530,097. Patented-Dec. 4, 1894.

E IQ E E Q E E E E E R F I: r- 9 k g E E 1Q I E E v E m E E TQ kWitnesses: inven or. WM

Attorhe 3 Sheets-Sheet '2.

(No Model.)

T. PARNSWORTH. GAS comrnnssme PUMP.

Patented Dec. 4, 1894' '(NoModL) 3 SheetsSheet 3.

' T. FARNSWORTH.

GAS GOMPRESSING PUMP.

No 530,097. Patented D 60. 4, 1894.

41 Inventor Attorn y.

Witnesses: W a.

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UNITED STATES PATENT OFFICE.

THOMAS 'FARNSWORTH, OF SAN ANTONIO, TEXAS.

GAS-COMPRESSING PUMP.

SPECIFICATION forming part of Letters Patent No. 530,097, dated December4, 1894.

Application filed February 26, 1894:. Serial No. 501,484- (No model.)

to which it appertains to make and use the same, reference being hadtothe accompany- 1ng drawings, and to the letters of reference markedthereon, which form a part of this specification.

My invention relates to pumps for exhausting and compressing gases, andhas especial reference to the pumps used in mechanical refrigeration andice making.

The object of my invention is to reduce the height of a verticalmachine, to facilitate access to the parts and relieve the foundation ofstrains; to reduce to a minimum the angularity of the connecting rodduring the latter part of the stroke, and to improve various details ofconstruction, as hereinafter set forth, and particularly pointed out inthe claims.

In the accompanying drawings, Figure lis a side elevation of a doublecylinder compressor embodying my improvements. Fig. 2 is a verticalsection thereof, and Fig. 3 is a 7 cross section on the axis of the rockshaft.

The cylinders A A are open at each end and are supported by flanges a onasuitable base B, consisting of preferably two parts united by a packedjoint I) on a horizontal plane. The upper portion of the base has twonecks b in which the cylinders are received, their lower ends dependinginto the base, as shown. The joint between the neck I) and the flange ais packed, so that the base forms a gas tight chamber. A pipe B,provided with a suit able stop valve, connects the base with theevaporating coils. The lower portion of the base is preferablyin onepiece, to form areservoir for lubricating oil. At B are covers to handholes for giving access to the bearings of the connecting rods. In eachcylinder, just below the flange a are one or more ports a. The upper endof each cylinder is closed by a check valve 0, which cuts off thecylinder from a chamber D from which proceeds a discharge pipe E havinga stop valve e and connecting with a common pipe E, running to thecondenser.

In each cylinder is a piston F, tubular in shape, and provided with anumber of packing ringsf. The upper end of the piston forms a seat foran upwardly closing valve G, which slides on vertical guides f on theinside of the piston. A ring f screwed into the lower end of the pistonlimits the play of the valve. A socket is formed in the under side ofthe valve to receive the ball h on the upper end of the connecting rodH, the ball being confined in the socket in any suitable manner, as by agland g. The lower end of the rod His provided with brasses h forconnecting it with a wrist pin a on a rocker I. The brasses can beadjusted by a wedge h and screw h The rocker I is keyed to a shaft K,journaled in bearings 17 integral with the lower portion of the base.The rocker has a working fit between the inner faces of these bearings,which are bored out cylindrically, and are lined with bushings L turnedto an outside fitin the bearings and bored out to suit the long andpreferably taper journalsk on theshaft K. A gas tight cover 12 inclosesone end of the shaft. The other end passes through a stuffing box B andis supported in an outboard pillow block M. The axis of the shaft liespreferably in the plane of the joint 5 between the upper and lowerportions of the base. Fastened to the shaft outside the base is a rockarm N, to which may be attached a rod to for connecting it with anengine or other motor.

The wrist pins i and shaft K are not in line with each other, but theshaft stands above the line joining the pins, so that each pin isdistant from the shaft more than half the distance between the axes ofthe cylinders A. The proportions are such that when a piston is at thebottom of its cylinder, as at the right of Fig. 2, the angularity of therod is the greatest; but when the piston hasmade half its up stroke, thepin '5 intersects the axis of the cylinder, and therod co-incides withsaid axis. The continued upward movement of the rocker arm swings therod slightly outward for the next quarter of the stroke, but during thelast quarter the rod again approaches a central position, which itreaches at the end of the stroke, as seen at the left of Fig. 2. Thedotted lines in this figure show the paths of the pins 2?. It thusappears that during the latter half of the stroke, when the resistanceof the gas in the cylinder is greatest, the angularity of the rod isleast, thus reducing to a minimum the wear and strain. It also appearsthat the line joining the center of the wrist pin and the axis of theshaft does not stand at right angles to the axis of the cylinder untilthreequarters of the stroke has been made.

In operation, the downward movement of the rod I-I first draws down thevalve G from its seat in the upper end of the piston. When the lower endof the valve strikes the ringf the piston is carried downward, the gasin the base passing into the cylinder past the open valve G. On arrivingat the bottom of its stroke, the piston uncovers the ports a, whichpermit the gas to enter the cylinder freely and insure a full charge atevapo' rating pressure. The upward movement of the rocker arm firstcloses the valve G and then carries up the piston, compressing the gasin the cylinder until it equals the pressure in the condenser, when thecheck valve 0 opens, and the gas passes into the condenser, where it isliquefied. The construction of the piston is such that there is perfectfreedom from restraint, avoiding unequal wear, and insuring prompt andcorrect action. The ball joints, guides in the pistons, pins and shaftbearings are all lubricated by the oil in thelower portion of the base,which is preferably carried at the height of the center of the shaft K,but may be varied to suit. The level of the oil is shown byagage 0. Ateach stroke, the descending rocker arm throws up a spray which amplylubricates the parts not immersed in the oil.

It will be seen that all the parts have large bearing surfaces, and thattheir movement is comparatively small, so that friction and wear arereduced to a minimum. The machine stands low and firm on its foundation.The stuffing-box B is easily kept tight, since it is exposed only to thelow evaporating pressure in the base.

In a former patent, No. 395,044, I have shown, described and claimed theconstruction of the piston, with its valve and ball socket.

What I now claim, and desire to secure by Letters Patent, is--- 1. Inasingle-actinggas-compressingpump, the combination with two parallelcylinders, and their pistons, of a rocker, and rods connecting the endsof said rocker with thepisto'ns, said rocker being pivoted between theaxes of said cylinders and at a point nearer to the pistons than ahorizontal plane intersecting the wrist pins on the ends of the rockers,said rods co-inciding with the axes of the cylinders when the pins standin said horizontal plane, substantially as described.

2. Inasingle actinggas compressing pump, the combination with a pumpcylinder, of a piston, a connecting rod, and a rocker arm for actuatingsaid rod pivoted on an axis so.

located that the line joiningthe end of the rod and said axis is atright angles to the axis of the cylinder when the piston has completedthe greater part of its stroke, substantially as described.

3. In a gas compressing pump, the combination with a pump cylinder, of apiston, a connecting rod, and a rocker pivoted at one side of thecylinder, so that at the middle and completion of the stroke theconnecting rod coincides with the axis of the cylinder, substantially asdescribed.

In testimony whereof Iaffix mysignature in presence of two witnesses.

THOMAS FARNSVVORTH.

\Vitnesses:

JAS. SCHUEHLE, Rosa. '1. TALIAFERRO.

